What Oatmeal Shampoo are you using? It's it's human shampoo, most are made with sulfates that dry out the skin.
I would switch to
Theraneemor
Earthbath Oatmeal and Aloe.
Adding
Fish Oils really help with the dry skin.
I would also add some
Great Life Digestive Enzymes to help your loved one absorb all the nutrients in the food, it also helped a lot with the dandruff.